[NOIP2013]华容道 又是爆搜

#include<cstdio>
#include<cstring>
#include<iostream>
#include<queue>
#define pos(i,a,b) for(int i=(a);i<=(b);i++)
#define N 101000
#define inf 0x3fffffff
using namespace std;
struct haha{
	int to,next,w;
}edge[N*2];
int head[N],cnt=1,n,m,qq,ji;
int xx[4]={1,-1,0,0},yy[4]={0,0,1,-1};
int flag[50][50],shu[50][50][5],a[50][50];
void add(int u,int v,int w){
	edge[cnt].w=w;
	edge[cnt].to=v;
	edge[cnt].next=head[u];
	head[u]=cnt++;
}
struct xixi{
	int x,y,step;
};
int bfs(int fx,int fy,int tx,int ty,int bx,int by){
	if(fx==tx&&fy==ty) return 0;
	memset(flag,0,sizeof(flag));
	queue<xixi> q;
	flag[fx][fy]=1;
	q.push((xixi){fx,fy,0});
	while(!q.empty()){
		int x,y,t;xixi temp=q.front();
		x=temp.x;y=temp.y;t=temp.step;
		q.pop();
		pos(k,0,3){
			if(a[x+xx[k]][y+yy[k]]&&(x+xx[k]!=bx||y+yy[k]!=by)&&flag[x+xx[k]][y+yy[k]]==0){
				if(x+xx[k]==tx&&y+yy[k]==ty) return t+1;
				q.push((xixi){x+xx[k],y+yy[k],t+1});
				flag[x+xx[k]][y+yy[k]]=1;
			}
		}
	}
	return inf;
}
int ex,ey,sx,sy,tx,ty;
int dis[N];
int spfa(){
	if(sx==tx&&sy==ty) return 0;
	pos(i,1,ji) dis[i]=inf;
	queue<int> q;
	pos(k,0,3)
		if(shu[sx][sy][k]){
			dis[shu[sx][sy][k]]=bfs(ex,ey,sx+xx[k],sy+yy[k],sx,sy);
			q.push(shu[sx][sy][k]);
		}
	while(!q.empty()){
		int temp=q.front();q.pop();
		for(int i=head[temp];i;i=edge[i].next){
			int to=edge[i].to;
			if(dis[to]>dis[temp]+edge[i].w){
				dis[to]=dis[temp]+edge[i].w;
				q.push(to);
			}
		}
	}
	int ans=inf;
	pos(k,0,3)
		if(shu[tx][ty][k])
			ans=min(ans,dis[shu[tx][ty][k]]);
	return ans==inf?-1:ans;
}
int main(){
	scanf("%d%d%d",&n,&m,&qq);
	pos(i,1,n) pos(j,1,m) scanf("%d",&a[i][j]);
	pos(i,1,n)
		pos(j,1,m)
			pos(k,0,3)
				if(a[i][j]&&a[i+xx[k]][j+yy[k]])
					shu[i][j][k]=++ji;
	pos(i,1,n)
		pos(j,1,m)
			pos(k,0,3)
				if(shu[i][j][k])
					add(shu[i][j][k],shu[i+xx[k]][j+yy[k]][k^1],1);
	pos(i,1,n)
		pos(j,1,m)
			pos(k,0,3)
				pos(l,0,3)
					if(k!=l&&shu[i][j][k]&&shu[i][j][l])
						add(shu[i][j][k],shu[i][j][l],bfs(i+xx[k],j+yy[k],i+xx[l],j+yy[l],i,j));
	while(qq--){
		scanf("%d%d%d%d%d%d",&ex,&ey,&sx,&sy,&tx,&ty);
		printf("%d\n",spfa());
	}
	return 0;
}